On 09/04/2013 01:59 AM, Jim Lux wrote: > On 9/3/13 11:21 AM, Poul-Henning Kamp wrote: >> In message <5225f8af.60...@earthlink.net>, Jim Lux writes: >> >>> In this case, all the messages were presumably handled by the same >>> carrier, so the issue of skew in timestamps is negligible; >> >> Anything but. >> >> The text-messages are likely stamped by the SS7-message-gateway >> and the 911 call by the countys 911 equipment. >> > > I was assuming (with no real basis, I realize) that the 911 call time > came from the cell equipment, rather than the Public Safety Answering > Point log. The PSAP log would have no particular reason to be synced > to the carrier equipment. It could well be "what time was on the watch > of the guy starting the equipment", although these days, one would > *think* that they use something like NTP to set the system time. > > However, given my frustrated experience trying to get folks doing > testbeds and ground support equipment here at JPL to *please* > synchronize your computers meaningfully so we can merge logs, I > wouldn't count on it. Or maybe they sync once every 24 hours. That would be luxury! There are so many systems out there ticking away at their free-running clocks, and that does not even have the capability of an external time source.
Cheers, Magnus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.